Table V.

Histological subtypes of DFSP as described by Kim (29).

Subtype	Histological characteristics	Clinical features
‘Classic’ DFSP	Monomorphous fusiform cells (spindle cells) with large elongated nucleus and poor cytoplasm, low mitotic index	Most common subtype (90%) Rare metastasis (≤0.5%)
Giant cell fibroblastoma	Giant multinucleated cells, sinusoidal vessels, myxoid stroma	Frequently observed in childhood
Bednar tumor	Melanocytes and deposits of melanin	Observed in African and American patients
Sclerotic DFSP	Abundant stroma with several layers of collagen and areas of denser cellularity	Rare subtype
Myxoid DFSP	Spindle cells grouped in nodules with eosinophilic cytoplasm	Rare subtype
Atrophic DFSP	Atrophic mid-dermis with subcutaneous tissue close to the epidermis	Frequently observed in childhood
Fibrosarcomatous DFSP	High mitotic index with high cellularity and marked nuclear pleomorphism	Subtype with the highest recurrence rate and metastatic potential, most aggressive variant

DFSP, dermatofibrosarcoma protuberans.